Apex Minutes for Minneapolis (IETF 50) 1. Welcome - Pete Resnick The chair announced that the working group had been formed two weeks earlier, and went over the agenda. Marshall Rose is taking the minutes. 2. "End-point Servers" proposal - Darren New A presentation was made suggesting an additional facility be layered on top of APEX - the equivalent of a well-known port facility for servers that are provisioned independently of the relaying mesh. The key technical issue is that the action tokens used by the APEX access service are keywords (not hierarchical entities). The proposal introduced a convention for allowing arbitrary services that use APEX to utilize the access service without working about conflicts. It was noted that it would also be useful if the access service would notify an endpoint when its access entry was updated, in order to facilitate caching. It was agreed that the presenter would prepare a draft proposal for the mailing list. In addition, it was noted that International University in Germany has an alternative approach, and might also document that proposal. 3. "Multicast APEX" - Jon Crowcroft A presentation was made on some design issues for overlaying application-layer multicast on top of APEX, noting that there was a lack of standards-based approaches available. The work is in it's early stages, although it raises some interesting issues. For example, since introducing multicasting to APEX will require the use of a dynamic unicast routing protocol, should such a facility also be available throughout the relaying mesh. It was noted that since the relaying mesh is option-driven, it's trivial to define an option that makes use of such a dynamic routing facility. 4. "General Issues" - Chris Newman An informal set of issues was raised: 4a. The use of subaddresses is ambiguous (i.e., the specification doesn't explicitly indicate what signifies a subaddress, thereby leading to the "longest same name" problem). The editor will clarify the text. 4b. The relay-relay mode requires that an APEX relay have an entry in the DNS. This is problematic for single users whose ISP don't run APEX and don't allow dns updates. It was noted that the DNS dependency would go away if Step 2 of Section 4.4.2 (the bind operation) didn't rely on a reverse-lookup. It was suggested that third-party ISPs may offer APEX service (e.g., ISP1 is what you use to get IP connectivity with, and ISP2 runs an APEX service that you subscribe to as an endpoint). The chair invites comment. 4c. seeNoEvil='false' is a double negative. The editor will change this to 'mustUnderstand', so compatibility with SOAP can be claimed. 4d. It was suggested (a) that the 'content=' attribute of the element is sent as a URL, which is not strictly necessary to use when the content is nested XML; and (b) that the internal referencing mechanism appears to disregard the XML ID/IDREF mechanisms. Responses: (a) the design is that 'content=' uses a consistent URI-based mechanism for both internal and external references. The internal reference, in the form of a fragment identifier, uses XPointer URI fragment mechanism which in turn uses XPath, and (b) the 'Name=' attribute of is declared in the DTD to have the XML attribute type ID, which is picked up by the XPointer fragment reference. Thus, this proposal is intended to use a form that is compatible with emerging XML developments; in the absence of further discussion, no further change is necessary. 4e. It was noted that supporting per-recipient capabilities would be welcome. It was asked whether the presence service could provide this facility. It was noted that if so, then the presence service probably needs to allow selective retrieval of a presence entry. The chair invites proposals in the form of Internet-Drafts. 5. "Options" - Marshall Rose It was observed that the relaying mesh is option driven and that the APEX core provides the simplest default mechanisms. Although several parties have privately suggested options for consideration, none of these proposals have circulated publically. The chair invites proposals. 6. Adjourn - Pete Resnick